WO1996035652A1

WO1996035652A1 - Emulsions of organosilicon compounds for making building materials hydrophobic

Info

Publication number: WO1996035652A1
Application number: PCT/EP1996/001993
Authority: WO
Inventors: Hans Mayer; Ingeborg König-Lumer
Original assignee: Wacker-Chemie Gmbh
Priority date: 1995-05-11
Filing date: 1996-05-10
Publication date: 1996-11-14
Also published as: ATE188685T1; TW440591B; ES2143205T3; DE59604176D1; EP0824510B1; US6262171B1; DE19517346A1; EP0824510A1

Abstract

The proposed aqueous emulsions contain the following components: components (A), selected from (A1) C1-C20- alkyl-C2-C6-alkoxysilanes and (A2) alkoxy groups containing organopolysiloxane; (B) organopolysiloxane which in addition to other organosiloxane units contains siloxane units with SiC-bonded groups containing basic nitrogen, a condition being that the amine value of the organopolysiloxane is at least 0.01; and (C) emulsifier. The said emulsions are used for making porous mineral building materials hydrophobic.

Description

Emulsions of organosilicon compounds for the hydrophobization of building materials

The invention relates to aqueous emulsions of organosilicon compounds for the hydrophobization of porous mineral building materials, and to a process for hydrophobizing the building materials with the emulsions.

Aqueous emulsions of organosilicon compounds are used in building protection mainly because of their excellent impregnation against water and dirt, their environmental compatibility and physiological harmlessness.

US Pat. No. 4,757,106 describes the impregnation of neutral mineral building materials with an aqueous emulsion of polyorganosiloxane containing ammonium groups and polyorganosiloxane containing ethoxy groups. The hydrophobic effect is lower on alkaline building materials, since the ammonium groups are neutralized and the emulsion breaks. The polyorganosiloxanes can then hardly penetrate the building material.

Emulsions which contain resinous, alkoxy group-containing polyorganosiloxanes as active ingredients penetrate well into porous building materials and give them good surface hydrophobicity. However, dense building materials are only protected on the surface and for a limited period of time.

Emulsions of alkylalkoxysilanes penetrate building materials well, but are not stable in storage. EP-A-340 816 describes buffered emulsions of alkylalkoxysilanes which, although stable in storage, separate too slowly, particularly in neutral building materials, and are therefore poorly hydrophobic.

Emulsions which contain resinous, alkoxy group-containing polyorganosiloxanes and alkylalkoxysilanes as active ingredients are known from US Pat. No. 5,091,002. These emulsions are a compromise between shelf life and a hydrophobic effect on the surface.

The previously known emulsions, which contain no polyorganosiloxane containing ammonium groups, are not very stable in diluted form and show unsatisfactory resistance to early water.

The invention has for its object to provide storage-stable aqueous emulsions of organosilicon compounds for the hydrophobization of porous mineral building materials and building coatings, as well as a method for hydrophobicizing porous mineral building materials and building coatings, which is particularly effective with neutral and basic building materials and building coatings.

The invention relates to an aqueous emulsion containing the components (A) which are selected from

(AI) Cι-C2o ~ ^A lkyl-C2-C6-alkoxysilanes and

(A2) organopolysiloxane containing alkoxy groups,

(B) organopolysiloxane, which contains, in addition to other organosiloxane units, those siloxane units which have SiC-bonded radicals containing basic nitrogen, with the proviso that the amine number of the organopolysiloxane is at least 0.01, and

(C) contains emulsifier.

Preferably, the C ₁ -C2o-alkyl-C2-C6-alkoxyεilane (AI) 1 or 2 are identical or different, gegebenenf lls halogen-substituted, SiC-bonded monovalent _Cι-C2o ~ alkyl radicals and the remaining radicals are identical or verschie¬ their C2-Cg alkoxy radicals. Methoxysilanes hydrolyze too quickly and prevent sufficient shelf life.

Examples of the C _] _-C2o ~ alkyl radicals are the methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, neo-pentyl, tert-pentyl radical; Hexyl radicals, such as the n-hexyl radical; Heptyl residues, such as the n-heptyl residue; Octyl radicals, such as the n-octyl radical and iso-octyl radicals, such as the 2, 2,4-trimethylpentyl radical; Nonyl radicals, such as the n-nonyl radical; Decyl residues, such as the n-decyl residue and do-decyl residues, such as the n-dodecyl residue; Cycloalkyl residues, such as cyclopentyl, cyclohexyl, 4-ethylcyclohexyl, cycloheptyl residues, norbornyl residues and methylcyclohexyl residues.

Examples of halogen-substituted C ₁ -C ₂ o ~ ^A -l y ^k ^lreste are radicals having fluorine, chlorine, bromine and iodine substituted also alkyl, such as 3, 3,3-trifluoro-n-propyl, 2,2,2,2 ', 2', 2'-hexafluoroisopropyl and the heptafluoroisopropyl.

Particularly preferred are the non-substituted C ₁ -C ₁ 2 ~ ^A ^ - ~ kylreste.

Examples of C ₂ -Cg alkoxy radicals are the ethoxy, n-propoxy, isopropoxy, n-butoxy, iso-butoxy, sec-butoxy, ^' tert-butoxy radical; Pentyloxy radicals, such as the n-pentyloxy radical and hexyloxy radicals, such as the n-hexyloxy radical. The ethoxy radicals are particularly preferred.

The alkoxy radicals can be substituted with halogen atoms, but this is not preferred.

The emulsion can contain an organopolysiloxane (A2) containing alkoxy groups or a mixture of several organopolysiloxanes. The organopolysiloxanes can additionally contain hydroxyl groups, which facilitate binding to the building materials.

The organopolysiloxanes (A2) preferably have a viscosity of at most 2000 mm ² / s in order to achieve a particularly good distribution on the pore surfaces in the masonry.

The organopolysiloxanes (A2) from units of the general formula (I) are particularly suitable

R _χ Si (OR-) _y (OH) _z 0 ₄ _ _χ _ _y . _z (I) in the

R same or different monovalent, optionally halogen-substituted, via SiC-bonded

hydrogen radicals, R ¹ identical or different monovalent Ci-Cg-alkyl radicals, x 0, 1, 2 or 3, on average 0.8 to 1.8, y 0.1 2, or 3, on average 0.01 to 2.0 and z means 0, 1, 2 or 3, on average 0.0 to 0.5, with the proviso that the sum of x, y and z is at most 3.5.

The organopolysiloxane (A2) preferably has a viscosity of 10 mm ² / s to 50,000 mm ² / s, in particular 50 mm ² / s to 5000 mm ² / s at 25 ° C.

Examples of that

are the C listed above for the organoalkoxysilanes (AI) ₁ ~ -C2o alkyl radicals and halogen-substituted _C] _- C ₂ o ~ ^A1 alkyl- radicals, alkenyl radicals such as the vinyl, allyl, n-5-hexenyl, 4 Vinylcyclohexyl and the 3-norbornenyl radical; Aryl radicals, such as the phenyl, biphenylyl, naphthyl and anthryl and phenanthryl radical; Alkaryl groups such as o-, m-, p-tolyl groups, xylyl groups and ethylphenyl groups; Aralkyl radicals, such as the benzyl radical, the alpha and the β-phenylethyl radical. The unsubstituted C 1 -C ₂ -alkyl radicals and the phenyl radical are particularly preferred.

Although not listed in the formula above, some of the radicals R can be replaced by hydrogen atoms bonded directly to silicon atoms. However, this is not preferred.

Examples of the radicals R ¹ are the methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, and tert.-butyl radical; Pentyl radicals, such as the n-pentyl radical and hexyl radicals, such as the n-hexyl radical, the ethyl radicals being particularly preferred.

Preferably x has an average value of 0.9 to 1.1. Preferably y has an average value of 0.4 to 1.2. Z preferably has an average value of 0.0 to 0.2.

Examples of organosiloxanes (A2) are those which, by reaction of methyltrichlorosilane and optionally a _C] _- Cg-alkyltrichlorosilane, phenyltrichlorosilane or are available with ethanol in water, such as the organopolysiloxanes of the empirical formulas

CH ₃ Si (OC ₂ H5) _{0 8} O _1/1 or

C ₆ H ₅ Si (OC2H5) _0f7 2θ _1/14 .

The organopolysiloxanes (B) are preferably those from units of the general formula (II)

R ² _a R ³ _b (0R) _c Si0 ₄ _ _a _ _b _ _c (II),

in the

R ² same or different monovalent, from basic

Nitrogen-free, optionally halogen-substituted, SiC-bonded -CC-C2o ~ hydrocarbon radicals means

R ³ _{denotes the} same or different monovalent, optionally halogen-substituted, SiC-bonded basic nitrogen- _containing C _] _-C _3Q hydrocarbon radicals,

R ^{4 can be the} same or different and hydrogen atom or Ci _^ -Cg alkyl radicals, a 0, 1, 2 or 3, b 0, 1, 2 or 3, on average at least 0.05 and c 0, 1, 2 or 3, with the proviso that the sum of a, b and c is less than or equal to 3 and that the amine number of the organopolysiloxane (B) is at least 0.01.

The amine number denotes the number of ml of 1-N-HCl which are required to neutralize 1 g of organopolysiloxane (B). The amine number of the organopolysiloxane (B) is preferably at least 0.1, in particular at least 0.2, and preferably at most 8, in particular at most 4.

Examples and preferred examples of the radical R ² are listed above for the radical R. In particular, the methyl and isooctyl radicals are preferred.

A hydrocarbon radical, in particular a methyl radical, is preferably also bonded to each silicon atom to which a hydrogen atom is bonded.

The radical R ³ is preferably a radical of the general formula (III)

R ⁵ ₂ NR ⁶ - (III),

wherein

R ^{5 can be the} same or different and hydrogen or monovalent, optionally substituted Cιo ~ hydrocarbon residue or Cτ_-Cιo-amino hydrocarbon residue and R ^{6 means} a divalent C 1 -C 5 hydrocarbon radical.

Examples of radical R ⁵ are the examples given for radical R for hydrocarbon radicals and hydrocarbon radicals substituted with amino groups, such as aminoalkyl radicals, the aminoethyl radical being particularly preferred.

At least one hydrogen atom is preferably bound to each nitrogen atom in the radicals of the general formula (III).

The radical R ⁶ is preferably a divalent hydrocarbon radical having 1 to 10 carbon atoms, particularly preferably 1 to 4 carbon atoms, in particular the n-propylene radical.

Examples of radical R ⁶ are the methylene, ethylene, propylene, butylene, cyclohexylene, octadecylene, phenylene and butenylene radical.

Preferred examples of radicals R ³ are

H ₂ N (CH ₂₎ ₃ _-.

H ₂ N (CH ₂ ) 2NH (CH ₂ ) ₂ -,

H ₂ N (CH ₂ ) ₂ NH (CH ₂ ) ₃ -,

H ₂ N (CH ₂ ) ₂ -,

H ₃ CNH (CH ₂ ) ₃ -,

C ₂ H ₅ NH (CH ₂ ) ₃ -,

H ₃ CNH (CH ₂ ) ₂ -,

C ₂ H ₅ NH (CH ₂ ) ₂ -,

H ₂ N (CH ₂ ) ₄ -,

H ₂ N (CH ₂ ) ₅ -,

H (NHCH ₂ CH ₂ ) ₃ -,

C ₄ H ₉ NH (CH ₂ ) ₂ NH (CH ₂ ) ₂ -, cyclθ-C ₆ H ₁₁ NH (CH ₂ ) ₃ -, cyclo-C ₆ HnNH (CH ₂ ) 2-, (CH ₃ ) ₂ N (CH ₂ ) ₃ -, (CH ₃ ) ₂ N (CH ₂ ) ₂ -, (C ₂ H5) ₂ N (CH2) ₃ - and (C ₂ H ₅ ) ₂ N (CH2) 2- •

The examples of alkyl radicals R ^{1 also} apply in full to the radical R ⁶ .

Examples and preferred examples of the R ⁴ radical are listed above for the R ¹ radical. In particular, the methyl and ethyl radicals are preferred.

The preferred average value for a is 0 to 2, especially 0 to 1.8.

The preferred average value for b is 0.1 to 0.6, especially 0.15 to 0.30.

The preferred average value for c is 0 to 0.8, especially 0.01 to 0.6.

The organopolysiloxanes (B) preferably have a viscosity of 5 to 5000, in particular 100 to 3000 mm ² / s at 25 ° C.

Organopolysiloxanes (B) can be prepared in a known manner, for example by equilibrating or condensing amino-functional silanes with organopolysiloxanes which contain alkoxy groups and / or hydroxyl groups and which are free of basic nitrogen.

The aqueous emulsions contain an emulsifier (C) known per se. The following are particularly suitable as anionic emulsifiers:

1. Alkyl sulfates, especially those with a chain length of 8 to 18 carbon atoms, alkyl and alkaryl ether sulfates with 8 to 18 carbon atoms in the hydrophobic radical and 1 to 40 ethylene oxide (EO) or propylene oxide (PO) units.

2. sulfonates, especially alkyl sulfonates with 8 to 18 carbon atoms, alkylarylsulfonates with 8 to 18 carbon atoms, taurides, esters and half-esters of sulfosuccinic acid with monohydric alcohols or alkylphenols with 4 to 15 carbon atoms; if appropriate, these alcohols or alkylphenols can also be ethoxylated with 1 to 40 EO units.

3. Alkali and ammonium salts of carboxylic acids with 8 to 20 carbon atoms in the alkyl, aryl, alkaryl or aralkyl radical.

4. partial phosphoric acid esters and their alkali and ammonium salts, especially alkyl and alkaryl phosphates with 8 to 20 carbon atoms in the organic radical, alkyl ether or alkaryl ether phosphates with 8 to 20 carbon atoms in the alkyl or alkaryl radical and 1 to 40 EO units.

The following are particularly suitable as nonionic emulsifiers:

5. Polyvinyl alcohol which still has 5 to 50%, preferably 8 to 20% vinyl acetate units, with a degree of polymerization of 500 to 3000.

6. Alkyl polyglycol ethers, preferably those with 8 to 40 EO units and alkyl radicals with 8 to 20 C atoms.

7. Alkylaryl polyglycol ethers, preferably those with 8 to 40 EO units and 8 to 20 C atoms in the alkyl and aryl radicals. 8. ethylene oxide / propylene oxide (EO / PO) block copolymers, preferably those with 8 to 40 EO or PO units.

9. Addition products of alkylamines with alkyl radicals of 8 to 22 carbon atoms with ethylene oxide or propylene oxide.

10. Fatty acids with 6 to 24 carbon atoms.

11. Alkyl polyglycosides of the general formula R * -0-Z _o , in which R * is a linear or branched, saturated or unsaturated alkyl radical with an average of 8-24 carbon atoms and Z _{0 is} an oligoglycoside radical with an average of o = 1-10 Mean hexose or pentose units or mixtures thereof.

12. Natural products and their derivatives, such as lecithin, lanolin, saponins, cellulose; Cellulose alkyl ethers and carboxyalkyl celluloses, the alkyl groups of which each have up to 4 carbon atoms.

13. Linear organo (poly) siloxanes containing polar groups, in particular those with alkoxy groups with up to 24 C atoms and / or up to 40 EO and / or PO groups.

The following are particularly suitable as cationic emulsifiers:

14. Salts of primary, secondary and tertiary fatty amines with 8 to 24 carbon atoms with acetic acid, sulfuric acid, hydrochloric acid and phosphoric acids.

15. Quaternary alkyl and alkylbenzene ammonium salts, in particular those whose alkyl group has 6 to 24 carbon atoms, in particular the halides, sulfates, phosphates and acetates. 16. Alkylpyridinium, alkylimidazolinium and alkyloxazolinium salts, in particular those whose alkyl chain has up to 18 carbon atoms, especially the halides, sulfates, phosphates and acetates.

The following are particularly suitable as ampholytic emulsifiers:

17. Long-chain substituted amino acids, such as N-alkyl-di (aminoethyl) glycine or N-alkyl-2-aminopropionic acid salts.

18. Betaines, such as N- (3-acylamidopropyl) -N, N-dimethylammonium salts with a Cg-Ciβ-acyl radical and alkyl imidazolium betaine.

Preferred emulsifiers are nonionic emulsifiers, in particular the addition products of alkylamines with ethylene oxide or propylene oxide listed above under 9, the alkyl polyglycosides listed above under 11 and the polyvinyl alcohol listed above under 5. Particularly preferred polyvinyl alcohols still contain 5 to 20%, in particular 10 to 15%, vinyl acetate units and preferably have a degree of polymerization of 500 to 3000, in particular from 1200 to 2000.

The total amount of components (A) and (B) in the aqueous emulsions is preferably 1 to 80% by weight, in particular 10 to 75% by weight, especially 30 to 70% by weight.

The proportion of emulsifier (C) is preferably 0.1 to 30% by weight, in particular 2 to 10% by weight, of the total amount of components (A) and (B).

The emulsions can additionally contain customary fillers and thickeners, in particular reinforcing fillers, that is fillers with a BET surface area of more than 50 m / g, such as pyrogenic silica, precipitated silica and silicon-aluminum mixed oxides with a large BET surface area. Highly disperse silica is particularly suitable. It can be a type of filler, a mixture of at least two fillers can also be used. The proportion of fillers is preferably at most 5, in particular 2,% by weight of the total amount of components (A) and (B).

The emulsions can also contain buffer substances which stabilize the pH in the range from 5 to 8, in which the alkyltrialkoxysilanes are very resistant to hydrolysis. All organic and inorganic acids and bases which are chemically inert towards the other constituents of the emulsions are suitable, in particular the alkali, alkaline earth and ammonium salts of carboxylic acids, phosphoric, carbonic and sulfuric acids. Sodium carbonate, sodium hydrogen carbonate, sodium hydrogen phosphate and a mixture of acetic acid and aqueous ammonia solution are particularly preferred. The preferred amount of buffer substances is preferably at most 3, in particular 1% by weight of the total amount of components (A) and (B).

In addition to the constituents described above, the emulsions can contain, as additives, fungicides, bactericides, algicides, microbicides, odorous substances, corrosion inhibitors and defoamers. The preferred amount of additives is at most 2, in particular 0.5,% by weight of the total amount of components (A) and (B).

The aqueous emulsions according to the invention are produced by customary processes for the preparation of aqueous emulsions. Preferably, only part of the water is first mixed with emulsifier (C), then component (B) and finally component (A) are emulsified until a viscous oil phase is formed and then the rest Water was added to form a less viscous emulsion. Components (A) and (B) can also be mixed and added to an emulsion of emulsifier and water. The mixing is preferably carried out in pressure emulsifying machines, colloid mills or in particular in a high-speed stator-rotor stirring device according to Prof. P. Willems.

The invention also relates to a process for the hydrophobization of porous mineral building materials and building coatings, in which the building materials and building coatings are treated with the above aqueous emulsion.

The invention also relates to a process for the hydrophobization of coating compositions forming porous mineral building coatings, in which the above-mentioned aqueous emulsion is added to the coating compositions.

The emulsions are suitable for the hydrophobization of mineral building materials, such as natural or artificial stone, concrete, cement, sand-lime brick and aerated concrete, building materials made of clay minerals, such as brick, as an additive to render gypsum, plastering and in building materials ten coatings, such as mineral paints, silicone resin emulsion paints and plasters, dispersion silicate paints, emulsion paints, coating fillers, reinforcing compounds and primers. In particular, the early rain resistance is improved for architectural coatings.

The emulsions are also suitable for the hydrophobization of finely divided inorganic substances such as perlite, ver iculit and thermal insulation materials.

The emulsions are particularly suitable for hydrophobizing mineral-bound, preferably cement-bound Fiber building materials, the fibers of which consist of natural fibers or synthetic fibers. Suitable natural fibers are mineral fibers such as rock wool, quartz or ceramic fibers or vegetable fibers such as cellulose. Suitable synthetic fibers are, for example, glass fibers, plastic fibers and carbon fibers. It is particularly preferred to use the emulsion for waterproofing cement-bound cellulose fiber components. The cellulose fibers can be, for example, jute, coconut or hemp fibers or come from paper, cardboard or waste paper.

The emulsions are suitable for bulk use, i.e. the emulsion is added to a hydraulic mixture for the production of components before setting or for the hydrophobization of components after setting.

The emulsions according to the invention can be diluted with water before they are used as water repellents and optionally binders. When impregnating the surface of building materials after setting, dilution up to a total content of components (A) and (B) of 1% by weight is advantageous.

In the following examples, all parts and percentages are by weight unless otherwise stated. Unless otherwise stated, the examples below are carried out at a pressure of the surrounding atmosphere, that is to say at about 0.10 MPa, and at room temperature, that is to say at about 20 ° C., or at a temperature which is zero when the reactants are combined at room temperature sets additional heating or cooling. All viscosity data given in the examples refer to a temperature of 25 ° C. The solid content of the emulsions denotes the sum of all components, with the exception of water.

Examples

The following are used as component (A):

Hl: iso-octyltriethoxysilane

H2: organopolysiloxane of the empirical formula CH ₃ Si (OC ₂ H5) o, ₈ ° _l, _l having an average molecular weight of about 650 g / mole and a viscosity of about 20 mm ² / s.

H3: As a high-viscosity liquid resin from vorliegendes Methylsilicon¬ CH3Siθ3 / 2 units, approximately 20 mol% of _(CH3) 2Si0 _2/2 units and about 10 mole% C2H5θSiθ _3/2 "units and a molecular weight of about 5000 g / mol.

H4: Methyl silicone resin in powder form

CH ₃ SiO _3/2 ~ ^nne ^E i th, ^m it about 3 mole% of units (CH ₃₎ 2Siθ2 / 2 ~ in- and about 4 mole% C2H5θSiθ _3/2 ~ NIT, a molecular weight of about 5000 g / Mol and a softening point of about 50 ° C.

The following are used as component (B):

Nl: condensation product of an α, ω-dihydroxymethylpolysiloxane and N (-2-aminoethyl) -3- aminopropyltrimethoxysilane in the presence of KOH with an amine number of about 0.3 and a viscosity in the terminal units each having a Si-bonded hydroxyl group of about 1500 mm ² / s at 25 ^β C and a residual methoxy content of less than 5 mol%, based on the methoxy groups initially present in the N (-2-aminoethyl) -3-aminopropyltrimethoxysilane. N2: condensation product analogous to Nl, but with an amine number of about 0.6, a viscosity of about 2000 mm ² / s at 25 ° C.

N3: condensation product of H2 and N (-2-aminoethyl) -3- aminopropyltrimethoxysilane in the presence of KOH with an amine number of about 3.0, a viscosity of about 500 mm ² / s at 25 ° C. and a residual methoxy content of less than 5 mol%, based on the methoxy groups initially present in the N (-2-aminoethyl) -3-aminopropyltrimethoxysilane.

The following are used as component (C):

El: Genamin ^R 200 from Hoechst AG, Frankfurt, a reaction product made from stearylamine and ethylene oxide

E2: Glukopon ^R 225 from Henkel KGaA, Düsseldorf, a fatty alcohol C8-C10 glycoside in aqueous solution

E3: Polyviol ^R W 25/140 from Wacker-Chemie GmbH, Munich, a polyvinyl alcohol with a degree of polymerization of about 1600, which still has 11-14% acetoxyethylene units

Production of the external emulsions

The aqueous emulsions according to the invention are prepared by first mixing some of the water with emulsifier and emulsifying amino-functional polysiloxane followed by silane and / or silicone resin. Both the above-mentioned mixing and the emulsification take place in a high-speed stator-rotor stirring device after Prof. P. Willems. The compositions are listed in Table I below.

Table I

The emulsions EM 1 to EM 10 show no phase separation after 14 days of storage at 50 ° C., likewise after 6 months of storage at room temperature. So they are stable in storage.

The very good water repellency effect is remarkable if dilutions of emulsions EM 1 to EM 10 with an active ingredient content of about 1 to 10% are applied to mineral surfaces. Contact angles of> 90 ° are measured on the treated surfaces. Preparation of the emulsions not according to the invention

The emulsions not according to the invention were prepared analogously to the emulsions according to the invention. The compositions are listed in Table II below.

Table II

Example 1: Water repellant for porous mineral building materials

Emulsions according to the invention and not according to the invention are diluted with water to the solids content shown in Table III below.

Before use on porous mineral building materials, emulsions according to the invention and not according to the invention are stored for ₁₄ days at 50 ° C. and visually assessed. The symbols listed in Table III below have the following meanings: +++: no optical change

++: slight agglomeration (creaming), reversible by shaking +: strong agglomeration (creaming), reversible by shaking: irreversible phase separation by coalescence.

Storage of the emulsions for 6 months at room temperature causes the same changes.

The emulsions are applied to lime sandstone coated with mineral paint (silicate paint Purkristallat ^R from Keimfarben GmbH, Diedorf) by application with a brush. After 14 days of storage at room temperature, the discoloration of the coated and hydrophobized limestone and the beading effect of dripped water are assessed by measuring the contact angle. Contact angles of> 90 ° indicate good beading effects and contact angles of <90 ° indicate rather poor beading effects. The results are shown in Table III below.

Hardened concrete test specimens are immersed in the emulsions for 1 minute. After 14 days of storage at room temperature, the test specimens are broken. The thickness of the hydrophobic zone on the surface denotes the depth of penetration. With the depth of penetration, the water absorption of the concrete decreases and at the same time its hydrophobicity increases. The results are shown in Table III below.

The emulsions are applied to sand-lime brick by application with a brush. After 14 days of storage at room temperature, the water absorption is assessed by measuring the water absorption coefficient w according to DIN 52617. Values w <0.1 kg / m ² xs ^{^1/2} denote an extremely low water absorption.

Example 2: Hydrophobizing G-rounding agent for mineral coatings on mineral building materials

Emulsion EM 2, diluted to a solids content of 10% by weight, is applied to sand-lime brick at 400 g / m ² . After 14 days of storage at room temperature, the following properties of the hydrophobized sand-lime brick are measured analogously to Example 1:

Water repellent effect: very good

Contact angle: 130 °

Penetration depth: 3 mm w value: 0.073 kg / m ² xs ^{^half} sd value: 0.02

The sd value was measured according to DIN 52615; sd values <0.1 m indicate high water vapor permeability, sd values> 0.1 m indicate reduced water vapor permeability.

The lime sandstone stored for 14 days is coated with silicone resin emulsion paint according to DIN 18363 (the content of organic resins does not exceed the content of organopolysiloxanes). Then the adhesive strength of the coating according to ISO 4624 is determined to be 2.8 N / mm ² . Without the hydrophobic primer with emulsion EM 2, 10%, the adhesion of this silicone resin paint to sand-lime brick is only determined at 1.5 N / mm ² .

Emulsion EM 7, diluted to a solids content of 10% by weight, is stored for 14 days at 50 ° C. and shows no optical change thereafter. This diluted emulsion is then applied by brush application to a 2 mm thick fiber cement board coated with crumbly lime cement plaster and then stored for 14 days at room temperature. The untreated lime cement, a w value of 1.3 kg / m ² xs found. ^{^1/2}

The following properties of the water-repellent lime cement plaster are found:

Water repellent effect: very good

Contact angle: 125 °

Penetration depth: 2 mm w value: 0.068 kg / m xs ^{^1/2}

What is striking is the improved surface strength of the lime plaster after the application of 10% EM 7.

The substrate treated in this way can be coated with silicone resin emulsion resin paints according to Example 3. After Q-UV rapid weathering of 1000 h, all of the preparations coated in this way show no spalling or changes in color while maintaining the very good beading effect.

Example 3: Water-repellent binders for aqueous facade paints and plasters

Silicone resin emulsion paints according to DIN 18363 and silicone resin plasters are examined here. These coating compositions belong to the class in which the content of organic resins does not exceed the content of organopolysiloxanes.

Conventional silicone resin paints and plasters initially still have a relatively high water absorption capacity for a certain period of time (“washout period”), which limits the initial resistance to weathering influences such as rain. The following demonstrates how the emulsions according to the invention impart early rain resistance to facade paints.

The production of emulsion paints is carried out with a dissolver. The quantity of water provided in the recipe is placed in the mixing container. The pigment wetting aids are added. The fillers and pigments are then added and predispersed for about 5 minutes. After the pigment and filler agglomerates have been broken up, the hydrophobizing emulsion is then stirred in and dispersed with the entire mixture for a further 5 minutes. As the last step, a polymer dispersion is added and the mixture is stirred in for 1 minute until homogeneous. The emulsion paint produced in this way is subsequently adjusted to processing consistency using thickeners.

Recipe

210.7 parts by weight of water

8.4 parts by weight of sodium polyphosphate solution (10% in

H ₂ 0) 1.4 parts by weight of pigment wetting aid (based on polyacrylic acid) 70.2 parts by weight of talc (particle size 20 μm) 70.2 parts by weight of precipitated calcium carbonate (average particle size 0.3 μm) 140.4 Parts by weight of calcium carbonate (filler calcite-type, average particle size 5 μm) 140.4 parts by weight of calcium carbonate (filler calcite-type, average particle size 15 μm) 140.4 parts by weight of titanium dioxide, rutile type 140.4 parts by weight of hydrophobicizing emulsion

56.2 parts by weight dispersion of styrene and acrylic acid ester, 50% in H2O (polymer dispersion)

21.3 parts by weight of thickener (hydroxyethyl cellulose 2.5% solution in H ₂ O)

1000.0 parts by weight

exam

Facade paints produced by the above process and recapture are examined for their water absorption. The suction effect of a building material or that of the composite building material / coating system is measured. The measurement of the capillary water absorption is described in DIN 52617. The procedure used here is carried out as a short test based on the above regulation. Limestone blocks (115x70x20 mm with a surface area of 0.008 m ² ) serve as the coating medium. When coating the paints, the first coat is poured 6.5 g onto the surface and evenly distributed with a flat brush, the side surfaces also being coated. The second coat of paint is applied every 24 hours. The amount of paint applied is 4.5 g. The coated test specimens are stored at room temperature for 24 hours and then at 50 ° C. for 24 hours. For further conditioning, there is an additional 24-hour storage at room temperature.

The test specimens prepared in this way are placed in trays which are lined with foam and filled with water in such a way that the painted surface remains in constant contact with the surface of the foam saturated with water. - 26 -

The weight gain is measured as a function of time (after 2.6 and 24 hours) and compared with that of the untreated test specimen.

reference

An untreated test specimen is subjected to water storage in accordance with the test method described

Duration of storage [hrs.] Water absorption [kg / m ² ] 2 2.98

6 3.01

24 3.1

Facade paint according to the invention

In the above recipe, the emulsions EM 4, EM 5 and EM 6 according to the invention are used undiluted in the amount specified in the recipe as the hydrophobizing emulsion. When testing for water absorption, the values listed in Table IV are found:

Table IV

Duration of storage water absorption [kg / m ² ]

(Hours) EM 4 EM 5 EM 6

2 0.15 0.10 0.20

6 0.25 0.20 0.35

24 0.33 0.33 0.45 Facade paint not according to the invention

A paint according to the recipe is produced by omitting the hydrophobicizing emulsion and by first in the water a silicone resin of the middle composition (CH3) i ^ Si O) 1.38 (OH) O, 04 ', its viscosity by adding 45 parts by weight of solvent naphtha was set to 2050 mPa · s (23 ° C.), using 8.4 parts by weight of a polyethylene oxide alkyla in as an emulsifier. Then the inorganic constituents etc. are dispersed.

Duration of storage water absorption [kg / m ² ] (hours)

2 0.40

6 2.90

24 3.10

This sample is then re-stored. The following values are then achieved with this second storage:

Duration of storage water absorption [kg / m ² ] (hours)

2 0.10

8 0.25

24 0.50

Example 4: Water-repellent additive for aqueous, highly filled facade paints and plasters

Here, highly filled, rather low-binder facade paints with high capillary water absorption are considered, as Disperεionssilikatfarben and plasters, highly filled coatings based on dispersion, Dispersionskalkfarben, ^S treichfüller and reinforcing compounds, mineral paints, plasters Mineral¬, whitewash etc. The pigment volume concentration ^(PVC) of the coatings is typically about _50%. Ü ^b Erlich enough, is the water absorption of the aforementioned coating agent is at least 3 kg / m ² to ₂₄ t _S _d. , _¬ be true to that described in Example 3 short test.

The addition of only 1% of the undiluted inventive _ß s emulsions Hydrophobierugsadditiv to those listed in Table V below coating agents, reduces this capillary water absorption dramatically. The water uptake WUR e _d determined by the short test in accordance with DIN 5 ₂ 6 ₁₇ sand-lime brick.

Table V

Coating additive Additive per [kg / m ² ] 1% by weight

Dispersion silicate paint 6.4 0.23 EM 3

Marsh lime plaster 7.4 0.35 EM 9

Dispersion paint 3.4 (PVK 70) 0.62 EM 10

Claims

claims

Aqueous emulsion containing the components

(A) which are selected from

(AI) C ₁ -C ₂ o ~ ^A lkyl-C ₂ -C ₆ -alkoxysilanen and

(A2) organopolysiloxane containing alkoxy groups,

(B) organopolysiloxane which, in addition to other organosiloxane units, contains those siloxane units which have residues with basic nitrogen which are bonded via SiC, with the proviso that the amine number of the organopolysiloxane is at least 0.01, and

(C) contains emulsifier.

Aqueous emulsion according to Claim 1, in which the C ₁ -C ₂ o -alkyl-C2-Cg-alkoxysilanes (Al) have 1 or 2 identical or different, optionally halogen-substituted, monovalent 0 ^ -0 _2Q- alkyl radicals bonded via SiC and the remaining radicals are the same or different C ₂ -Cg alkoxy radicals.

Aqueous emulsion according to Claim 1 or 2, in which the organopolysiloxanes (A2) consist of units of the general formula (I)

RxSi (0R ^x ) ^; y (OH) 'zO4, -xyz (I)

are constructed, in which R are identical or different monovalent, optionally halogen-substituted, SiC-bonded C ₁ -C ₂ o ~ h ^_ ^κ ° lenwasserstoffreste, R ^{1 are} identical or different monovalent Ci-Cg-alkyl radicals, x 0, 1, 2 or 3, on average 0.8 to 1.8, y 0, 1, 2, or 3, on average 0.01 to 2.0 and z 0, 1,

2 or 3 mean 0.0 to 0.5 on average, with the proviso that the sum of x, y and z is at most

Is 3.5.

4. Aqueous emulsion according to one of claims 1 to 3, in which the organopolysiloxanes (B) consist of units of the general formula (II)

R ² _a R ³ _b (OR4) _c Siθ ₄ _ _a _ _b _ _c (II),

are built in the

R ² same or different monovalent, from basic

Nitrogen free, optionally halogen substituted,. SiC-bonded Cι-C2o ~ l ^con ^enwassersto ff ^radicals,

R ³ denotes the same or different monovalent, optionally halogen-substituted, SiC-bonded basic nitrogen-containing C ₁ -C ₃ o ~ hydrocarbon radicals,

R ^{4 can be the} same or different and is hydrogen atom or Ci-Cg-alkyl radicals, a 0, 1, 2 or 3, b 0, 1, 2 or 3, on average at least 0.05 and c is 0, 1, 2 or 3, with the proviso that the sum of a, b and c is less than or equal to 3 and that the amine number of the organopolysiloxane (B) is at least 0.01.

5. An aqueous emulsion according to claim 4, wherein

Radical R ^{3 is} a radical of the general formula (III)

R ⁵ ₂ NR ⁶ - (III), in which R ^{5 can be} identical or different and is hydrogen or monovalent, optionally substituted CI ~ C ₁ -

Hydrocarbon residue or Cι ~ C ₁ o ~

Amino hydrocarbon radical and R ^{6 is} a divalent Ci-C - ^ - hydrocarbon radical.

6. Aqueous emulsion according to one of claims 1 to 5, in which the organopolysiloxanes (B) have a viscosity of 5 to 5000 mm ² / s at 25 ° C.

7. Aqueous emulsion according to one of claims 1 to 6, in which the emulsifier (C) is selected from polyvinyl alcohol, which still has 5 to 50% vinyl acetate units, with a degree of polymerization of 500 to 3000,

Addition products of alkylamines with alkyl radicals of 8 to 22 carbon atoms with ethylene oxide or propylene oxide and alkylpolyglycosides of the general formula R * -0-Z _o , in which R * is a linear or branched, saturated or unsaturated alkyl radical with an average of 8-24 carbon atoms and Z _{0 is} an oligoglycoside residue with an average of o = 1-10 hexose or pentose units or mixtures thereof.

8. Aqueous emulsion according to one of claims 1 to 7, in which the proportion of emulsifier (C) is 0.1 to 30 wt .-% of the total amount of components (A) and (B).

9. A process for the hydrophobization of porous mineral building materials and building coatings, in which the building materials and building coatings are treated with the aqueous emulsion according to claims 1 to 8.

10. A process for the hydrophobization of coating compositions forming porous mineral building coatings, in which the coating compositions are mixed with the aqueous emulsion according to claims 1 to 8.